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The site has a 155 m (509 ft) guyed steel lattice mast erected on land that is itself about 187 m (614 ft) above sea level. The radio broadcasts cover the majority of Pembrokeshire, except the north eastern part of the county. The signals also can reach the outskirts of Cardiff and the Vale of Glamorgan.
When UHF analogue television was added in 1990, those services were provided only at very low power and only designed to cover the small villages of Puncheston, Castlebythe, Little Newcastle and Rosebush, which are all located within about 7 km (4 mi) of the mast.
It currently carries three digital television multiplexes at twice the ERP of the analogue services that they replaced, thus providing digital TV to a much larger area than had been served before.
The 405-line VHF television system closed down permanently across the UK, and from then until Summer 1990, the site transmitted no television signals, just VHF (FM) radio.
18 July 1990 - 19 August 2009
Colour TV was added very late: Haverfordwest became a UHF relay of Presely. Being in Wales, this transmitter radiated the S4C variant of Channel 4.
Digital Switchover started at Haverfordwest, mirroring the changes at its parent transmitter at Presely. BBC2 closed on channel 66 and HTV Wales switched to that channel for its final three weeks of service. The BBC multiplex A started up on channel 56 vacated by ITV.
All the remaining analogue TV services closed and were replaced with the standard three multiplexes of Freeview Lite. Notice that unusually, the digital TV services are broadcast at twice the ERP that had been provided in the analogue TV days. At most sites, the digital services are broadcast at a fifth the ERP of the old analogue channels.
As a side-effect of frequency-changes elsewhere in the region to do with clearance of the 800 MHz band for 4G mobile phone use, Haverfordwest's "BBC B" multiplex was moved from channel 48 to channel 47. Additionally, all the transmissions at the site gained a +3 dB power boost.